Synchronized Threshing Drum Speed Control for Crop Conveyance
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Solution Overview
Problem
Existing threshing devices in combine harvesters lack precise positioning of the threshing drum and downstream drums, leading to inefficient crop stripping and conveying, resulting in reduced performance due to incomplete discharge and circulation of crop.
Innovation Solution
Synchronizing the circumferential speeds of adjacent drums to ensure opposite or slightly different leading/trailing positions of their strips, with a mechanical or electric drive connection to maintain slip-free operation, and adjusting the number of bars on downstream drums relative to the threshing drum to optimize crop stripping and conveying.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If no specific positioning of the threshing drum and turning drum is provided, then the drive design is simpler, but the crop stripping efficiency deteriorates due to incomplete discharge and circulation of crop
Solution Approach 1:
The patent applies parameter changes by synchronizing the circumferential speeds of adjacent drums and adjusting the positional parameters of strips. The control unit adjusts the rotational speeds of the threshing drum and turning drum to maintain optimal speed ratios, while the positioning mechanism adjusts the angular position of strips to ensure proper alignment. This resolves the contradiction by maintaining simple drive design while achieving high crop stripping efficiency through dynamic parameter adjustment.
2Device complexity
If the turning drum runs at the same speed as the threshing drum, then the drive system is simpler, but grain breakage increases due to improper strip positioning
Solution Approach 1:
The patent applies dynamics by implementing a control unit that dynamically adjusts the rotational speeds of the threshing drum and turning drum based on operating conditions. The system maintains optimal speed ratios rather than fixed equal speeds, allowing the drive system to adapt to varying crop types and throughput requirements. This resolves the contradiction by reducing grain breakage through dynamic speed control while keeping the drive system relatively simple through coordinated motor control.
3Ease of manufacture
If the strips of adjacent drums are not positioned oppositely, then the drum design is simpler, but crop conveying completeness deteriorates leading to circulation of crop
Solution Approach 1:
The patent applies preliminary action by using a positioning mechanism that pre-adjusts the angular position of strips on the turning drum relative to the threshing drum before the threshing process begins. The control unit calculates and sets the optimal positional offset to ensure strips are oppositely positioned, preventing crop circulation from the start. This resolves the contradiction by ensuring complete crop conveying through proper strip positioning while maintaining relatively simple drum design through fixed geometric relationships.
Data Source
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AI summary
The present invention relates to a threshing device for combine harvesters comprising a threshing drum (6), an associated threshing concave (7), and at least one drum (13) downstream of the threshing drum (6), which conveys the threshed crop from the threshing area and towards a residual grain separation device, wherein threshing bars (22) and bars (23) of the at least one downstream drum (13) are arranged at a distance from each other in the circumferential region of the threshing drum (6), wherein the circumferential speeds of adjacent drums (6, 13) are synchronized to each other such that the bars (22, 23) of adjacent drums (6, 13) always have a position opposite each other or a slightly deviating leading or lagging position in the turning and stripping area.